1) The dried crusty mucus secretion left in girls and women's undergarments, usually resulting from excessive stimulation of the vaginal area. Also known as "clitty litter".
2) A sissified boy who is afraid of getting hurt and will run away from confrontation.
see also - pussy, wussy, chicken shit

You should'a seen all the panty waste Mary left in her panties after I finger banged her.

(also: pantywaist; from Old English for Pantie-Waiste).
1. Panties up to or above the waist. i.e. old person panties.
2. Cumulative waste found in panties.
3. A waste of panties, as in expired panties.
4. The recipient of a wedgie, usually by surprise.
5. Trashed panties, specifically panties in the garbage.

-Oi there, you pug-pounding pantywaste!
-She is such a pantywaist, I simply do not approve.
-Will you have a gander at all of that pantie-waiste, such frivolity, I cannot imagine where you get off.
-I could not enter the forest for the pantywaste abound - some nearly up to my knees! I was forced to turn back.